Redaxscript is a free, PHP and MySQL driven content management system for small business and private websites. It's extremely lightweight, simple and customizable. Explore demo.redaxscript.com for a live preview.

Chabber is an extensible XMPP-based Instant Messaging application. It is a generic, portable application that follows the standard protocols for Instant Messaging and gives users a lot of advanced functionalities. It provides a platform for plugins.